Adjustable broach holder



N. H. IVERSEN ADJUSTABLE BROACH HOLDER Feb. 26, 1952 2 SHEETSSHEET 1 Filed Nov. 21, 1946 6 INVENTOR Norman ,H. Iversen ATTORNEYS Feb. 26, 1952 [VERSEN 2,587,570

ADJUSTABLE BROACH HOLDER Filed NOV. 21, 1946 2 SHEET SSHEET 2 THHIIIIII H] INVENTOR W an H Iversen 7 BY -h ATTORN EYS Patented Feb. 26, 1952 ADJUSTABLE BROACH HOLDER Norman H. Iversen, Birmingham, Mich., assignor to Production Broaching Corporation, Wayne County, Mich, a corporation of Delaware Application November 21, 1946, Serial No. 711,327

10 Claims.

This invention relates to adjustable broach holders and more particularly to a holder for adjustably mounting broach bars that are disposed radially with respect to a central axis for cutting splines, gears or the like.

The invention has for its object to provide means for simultaneously radially adjusting a series of angularly spaced broach bars.

A further object of the invention is to provide means associated with the broach bar adjusting means for indicating the amount of radial movement imparted to the bars.

A further object of the invention is to provide an adjusting device that is operable without releasing the bar clamping means.

With the above and other objects in view, the invention may be said to comprise the broach holder as illustrated in the accompanying drawings, hereinafter described and particularly set forth in the appended claims, together with such variations and modifications thereof as will be apparent to one skilled in the art to which the invention pertains.

Reference should be had to the accompanying drawings forming a part of this specification, in

which:

Figure l is a side elevation of a broach holder embodying the invention;

Fig. 2 is a central vertical section through the broach holder, taken on the line indicated at.

2-2 in Fig. 1;

Fig. 3 is a top plan view of the broach holder with portions of the cap broken away to show the assembly;

Fig. 4 is a fragmentary vertical section through the cap, taken on the line indicated at 4-4 in Fig. 3;

Fig. 5 is a fragmentary horizontal section taken on the line indicated at 55 in Fig. 2, and

Fig. 6 is a transverse section through the work guiding and broach bar positioning ring.

The broach holder of the present invention has a tubular body I provided with an enlarged bottom portion 2 provided with holes 3 to receive bolts for attaching it to a floor or other support.

The interior of the tubular body I is provided with internal cylindrical bearing portions 4 and 5 adjacent the upper and lower ends thereof and with a counterbore 6 at the bottom in which a base I fits. The base I is secured to the tubular body I, by means of bolts 8 and has a central projecting portion 9 that fits within the lower cylindrical portion 5 of the housing. The base 1 is provided with a central opening I0 through which the work may be passed and the top face thereof is provided with radial grooves II which are 'equiangularly spaced around the central opening I0. The radial grooves II have bottoms I2 that slant outwardly from the central opening I9.

Within the tubular body I above the base i there is mounted a follower I3 which has external cylindrical bearing portions I4 and It at its upper and lower ends which have a sliding fit within the cylindrical bearing portions 4 and 5 of the tubular body I. The tubular body I has an internally threaded portion I6 and the follower I3 has an externally threaded portion 'I'i that screws into the threaded portion I6 of the body. The follower I3 is moved axially within the tubular'body I upon turning movement by means of its threaded engagement with the tubular housing. The follower I3 has an upwardly tapering conical interior I8 which serves to position a series of vertically disposed upwardly tapering broach bars I9. Each of the broach'bars I9 has cutting teeth 20 along its inner edge and is provided with a straight slanting outer edge 2| that'engages the interior It or the follower. Each of the bars I9 has a lower end that fits in one of the grooves II and the lower ends of the bars I9 'are slanted to conform to the slanting bottoms I2 'of the grooves II.

The tubular body I is provided with a window 23 and the follower I3 has a series of angularly spaced sockets which are adapted to receive a suitable tool for. imparting turning movement to the follower and which are close enough together-so that one or more of the sockets is always accessible through the window 23. The exterior surface of the follower I3 is provided with a circumferential graduated scale 25 that moves past a stationary pointer Men the bottom of the window 23. Vertical adjustment of the followeri I3 serves to impart radial adjustment 'to' the broach bars I 9 and since the vertical adjustment of the follower is proportional to its angular movement, the scale '25 serves to indicate the amount of radial movements imparted to the broach bars. The broach bars I9 are clamped between the base I and a cap secured to the upper end of the tubular body I. The cap has an annular body portion 21 that is positioned upon the upper end of the body I by means of a dowel pin 28 and which is secured to the upper end of the tubular body I by means of attaching bolts 29.

guide ring 32 also serves to position the broach bars I9 and is provided on its under side with radial bar receiving slots 33. The exterior of the ring 32 has vertical slots 34 that form continuations of the bar receiving slots 33 and follower blocks 35 are slidably mounted in slots 34. In order to facilitate the assembly of the guide ring and blocks 35 in the cap, a retaining ring 35 is provided which encircles the ring 32 and holds the blocks 35 in the slots 34, the ring 33 being a spring ring which seats in a circumferential groove in the ring 32 and in vertically elongated recesses 38 in the outer sides of the blocks 35. The elongated recesses 38 permit the blocks 35 to have vertical movement in the slots 3 and these blocks are utilized to transmit clamping pressure to the upper ends of the broach bars I9.

The guide ring 32 is held in proper angular position with respect to the annular cap body 21 by means of radially disposed keys 39 that fit in radial slots All formed in the body 21 and which project into slots 34 of the ring 32, each of thekeys 38 being attached to the body 21 by means of a bolt 4|. An annular clamping ring 42 is secured to the annular body 21 by means of bolts 43 and is provided with a recessed under face 44 overlying the follower blocks 35. A cushioning ring 45 is seated in the recess 44 and is interposed between the upper ends of the blocks 35 and the clamping ring 42. The upper ends 46 of the broach bars I9 slant inwardly and the followers 35 have slanting lower ends 4'! that fit the slanting ends 46 of the broach bars.

Clamping pressure exerted against the 0ppositely slanting ends 22 and 46 of the breach bars I9 serves to clamp the bars I 9 tightly against the conical interior I8 of the follower I3, which provides a rigid backing for the broach bars during the passage of a work piece through the holder. The elastic cushioning ring 45 is adapted to yield when the bars I9 are simultaneously moved radially inwardly by downward movement of the follower I3 so that adjustments of the cutter bars may be made without releasing the bar clamping elements. The broach bars may be assembled in the holder and clamped in place with the cutting teeth at a slightly greater distance from the central axis than required for cutting the splines to full depth, after which the bars may be accurately adjusted to cut to the desired depth by turning the follower I3. When the bars are resharpened the removal of stock from the toothed edges of the bars can be compensated for by a radial adjustment of the bars. The bars may also be simultaneously adjusted inwardly for a finishing out.

It is to be understood that variations and modifications of the specific device herein shown and described for purposes of illustration, may be made without departing from the spirit of the invention.

What I claim is:

1. An adjustable broach holder comprising a tubular body, a base and a cap attached to opposite ends of saidbody and each provided with a central opening and positioning slots radiating from its central opening, broach bars having their ends fitting in said cap and base slots, said bars having toothed inner edges and slanting outer edges, an annular follower within said tubular body and engaging the slanting outer edges of said bars, and means for adjusting said follower axially of said body to radially adjust said bars.

2. An adjustable broach holder comprising a tubular body, a base and a cap attached to opposite ends of said body and each provided with a central opening and positioning slots radiating from its central opening, broach bars having their ends fitting in said cap and base slots, said bars having toothed inner edges and slanting outer edges, an annular follower within said tubular body and engaging the slanting outer edges of said bar, means for adjusting said follower axially of said body to radially adjust said bars, and means carried by said cap and base for clamping said bars and for exerting a radial outward thrust on said bars to hold them in engagement with said follower.

3. An adjustable broach holder comprising a tubular body, a base and a cap attached to opposite ends of said body and each provided with a central opening and positioning slots radiating from its central opening, broach bars having their ends fitting in said cap and base slots, said bars having toothed inner edges and slanting outer edges, said bars having oppositely slanting inwardly converging end faces, an annular follower within said tubular body and engaging the slanting outer edges of said bars, means for adjusting said follower axially of said body to radially adjust said bars, and means for applying clamping pressure to the slanting ends of said bars to hold the same against the interior of said annular follower.

4. An adjustable broach holder comprising a tubular body having internal screw threads, a cap and a base attached to opposite ends of the body and each having a central opening and slots radiating from its opening, a tubular internally conical externally threaded follower screwed into said body andaxially adjustable therein, and longitudinally tapering broach bars clamped between said cap and base with their ends guided for radial movements in said slots and their outer edges bearing against the conical interior of said follower.

5. An adjustable broach holder comprising a tubular body having internal screw threads and provided with a window, a tubular internally conical externally threaded follower screwed into said body and axially adjustable therein, said follower having turning tool sockets accessible through said window, a series of longitudinally tapering broach bars mounted within the follower, and means for holding said bars in spaced relation and against endwise movement with their outer edges in engagement with the conical interior of said follower.

6. An adjustable broach holder comprising a tubular body having internal screw threads and provided with a window, a tubular internally conical externally threaded follower screwed into said body and adjustable axially therein, said follower having turning tool sockets accessible through said window, a series of longitudinally tapering broach bars mounted within the fol lower, and cap and base members attached. to opposite ends of said body and having positioning slots to receive the ends of said bars and eng ng the ends of said bars to hold the same with their outer edges in engagement with said follower.

'7. An adjustable broach holder comprising a tubular body having internal screw threads and provided with a window, a, tubular internally conical externally threaded follower screwed into said body and axially adjustable therein, said follower having turning tool sockets accessible through said window, means for indicating the angular positions of said follower, a series of longitudinally tapering broach bars mounted within the follower with their outer edges engaging the conical interior of the follower, and means for positioning said bars in angularly spaced relation and for holding them against the interior of said follower.

8. An adjustable broach holder comprising a tubular body having internal screw threads and provided with. a window, a tubular internally conical externally threaded follower screwed into said body and, axially adjustable therein, said follower having turning tool sockets accessible through said window, a base secured to the lower end of said body below the lower end of the follower, said base having a central opening and grooves radiating from said opening, said grooves having outwardly slanting bottoms, longitudinal- 1y tapering broach bars having their lower ends fitting in said grooves and their outer edges bear ing against-said follower, a cap secured to the upper end of the casing and including a guide ring having radial slots to receive the upper ends of said broach ,bars, and means carried by said cap for clamping said broach bars against said base and against the interior of said follower.

9. An adjustable broach holder comprising a tubular body having internal screw threads, a tubular internally conical externally threaded follower screwed into said body and adjustable axially therein, a series of longitudinally tapering broach bars mounted within said follower with their outer edges engaging the conical "interior thereof, annular members mounted upon opposite ends of said body for positioning and clamping said bars, and elastic cushioning means interposed between one of said clamping members and the adjacent ends of said bars.

10'. An adjustable broach holder comprising a tubular body, a base attached to the lower end of said body, said base having a central opening and grooves in its top face radiating from said opening with their bottoms slanting from said central opening, an axially movable tubular fol lower mounted in said body, said follower having an upwardly tapering conical interior, broach bars mounted in said grooves and having toothed inner edges, said bars having slanting bottom and outer edges that conform to the bottoms of said grooves and the conical interior of said follower, an annular cap attached to the top of said body, said cap comprising an annular member having a central opening and a guide rin for said opening having radial slots that are adapted to receive the upper ends of said bars, vertically slidable blocks in said slots engageable with the upper ends of said bars, a clamping ring attached to the annular member and overlying said slots, and elastic cushioning means interposed between said clamping ring and said blocks.

NORMAN H. IVERSEN.

REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,909,840 Muller May 16, 1933 1,986,997 Bouillon Jan. 8, 1935 FOREIGN PATENTS Number Country Date 463,730 Great Britain Apr. 5. 1937 

